沿空巷旁支护适应性原理与支护方法
Adaptability theory of roadside support in gob-side entry retaining and its supporting design
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摘要: 沿空留巷作为无煤柱开采技术的重要组成,在薄及中厚煤层等条件下已经试验成功,但对于厚层坚硬顶板来压剧烈状况,沿空留巷效果差。本文在分析坚硬顶板岩梁剧烈运动特征的基础上,提出了沿空巷旁支护适应性原理,包括载荷适应性和变形适应性两方面;构建了"柔-强"组合巷旁支护力学结构模型,即采用柔性材料缓冲坚硬顶板先期剧烈沉降、高强材料承担顶板后期作用,发明了定量确定巷旁"柔-强"巷旁支护体分层厚度的方法;初步探讨了采空区矸石压缩与巷旁支护的流变协同力学特征,推导了采空区矸石压实稳定时间计算公式,分析了巷旁支护强层材料流变性能要求。现场试验表明,采用该方法实现了坚硬顶板条件下的沿空留巷,推动了无煤柱绿色开采技术进步。Abstract: As key part of no coal pillar mining,gob-side entry retaining is successfully applied in thin or medium thick- ness seam. However,it is not effective for quickly subsidence and dynamic pressure of hard roof beam. In order to solve the problem,the subsidence law was discussed and adaptability theory of roadside support in gob-side entry retaining was preliminary studied. The theory was explained by deformation and load. So,a new kind of roadside support model was constructed named “flexible-hard” combined wall,in which flexible materials were used to slow down hard roof beam quickly subsidence and hard materials were used as main support to afford its force. Then,the heights of flexible layer and hard layer were shown. The rheological synergy between caved rock and roadside support was used to esti- mate compaction stability time of caved rock and analyze rheological properties of hard supporting layer. By field test, it was successfully applied in hard roof and made great progress in green mining.